Distributed ledger systems (DLSs), which can also be referred to as consensus networks, and/or blockchain networks, enable participating entities to securely, and immutably store data. DLSs are commonly referred to as blockchain networks without referencing any particular user case. Examples of types of blockchain networks can include public blockchain networks, private blockchain networks, and consortium blockchain networks. A public blockchain network is open for all entities to use the DLS, and participate in the consensus process. A private blockchain network is provided for particular entity, which centrally controls read and write permissions. A consortium blockchain network is provided for a select group of entities, which control the consensus process, and includes an access control layer.
Blockchain is a decentralized and temper-proof distributed data storage technology. User data and contracts are logically operated and stored on the chain in a public manner. In many scenarios, users need to meet privacy protection requirements and do not want their data and logics to be leaked to unauthorized parties.
Although cryptography can be used to enhance privacy protection for some specific scenario designs, a more versatile and efficient solution is desired to solve existing privacy issues of the blockchain operations.